Hi, I have purchased the Windows 7 Professional to update from XP. I did all the pre-purchase downloads and checks, and got all the ticks. When installing the 64 bit DVD, I get the following error message Ã¢â‚¬Å“This installation disc isnÃ¢â‚¬â„¢t compatible with your version of Windows. To upgrade, you need the correct installation disc. For more information, check your computerÃ¢â‚¬â„¢s system information. To install a new copy of Windows, restart (boot) your computer using the installation disc, and the select Custom (advanced)Ã¢â‚¬Â, donÃ¢â‚¬â„¢t even get the option to custom install. I put the 32 bit DVD, custom installed and all worked OK. Put the 64 bit DVD and still get the same error. I am running 4GB Ram & 3.4GHz processor. Hoping someone can help as would really love to run W7 in 64-bit mode.